module pcmux(
    input jr, j, Pcscr, jal,
    input [31:0] pc4, JrAddr, JAddr, JalAddr, PscrAddr,
    output [31:0] CurrentPC
);
wire [31:0] w1, w2, w3;

assign w1 = (jr)? JrAddr:pc4;
assign w2 = (j)?  JAddr:w1;
assign w3 = (Pcscr)? PscrAddr:w2;
assign CurrentPC = (jal)? JalAddr:w3;

endmodule